381820281 has 4 divisors (see below), whose sum is σ = 509093712. Its totient is φ = 254546852.

The previous prime is 381820267. The next prime is 381820291. The reversal of 381820281 is 182028183.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 182028183 = 3 ⋅60676061.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-381820281 is a prime.

It is a super-2 number, since 2×381820281² = 291573453965837922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (381820291) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63636711 + ... + 63636716.

It is an arithmetic number, because the mean of its divisors is an integer number (127273428).

Almost surely, 2^381820281 is an apocalyptic number.

It is an amenable number.

381820281 is a deficient number, since it is larger than the sum of its proper divisors (127273431).

381820281 is a wasteful number, since it uses less digits than its factorization.

381820281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127273430.

The product of its (nonzero) digits is 6144, while the sum is 33.

The square root of 381820281 is about 19540.2221328213. Note that the first 3 decimals coincide. The cubic root of 381820281 is about 725.4703446586.

The spelling of 381820281 in words is "three hundred eighty-one million, eight hundred twenty thousand, two hundred eighty-one".